Axial compressors have inherently unsteady flow fields
because of relative motion between rotor and stator airfoils. This
relative motion leads to viscous and inviscid (potential) interactions
between blade rows. As the number of stages increases in a
turbomachine, the buildup of convected wakes can lead to progressively
more complex wake/wake and wake/airfoil interactions. Variations in
the relative circumferential positions of stators or rotors can change
these interactions, leading to different unsteady forcing functions on
airfoils and different compressor efficiencies. The current study uses
an unsteady, two-dimensional thin-layer Navier-Stokes zonal approach to
investigate the unsteady aerodynamics of stator clocking in a low-speed
þstage compressor. Relative motion between rotors and stators is
made possible by the use of systems of patched and overlaid grids.
Results include surface pressures instantaneous forces and efficiencies
for a þstage compressor conuration.